This invention is directed to a disposable absorbent pant having refastenable seams designed to minimize the likelihood of product tearing when forces are applied to separate the refastenable seams.
Disposable absorbent pants are used as a child's segue from diapers to underwear. Unlike diapers, which have high-cut leg openings with tabs or ears that fasten to the front of the waist area, disposable absorbent pants are designed to more closely resemble underwear with side seams on opposite sides of the garment that extend from a waist opening to well-defined leg openings. Consequently, diapers can be fastened to a wearer while the wearer is lying on his or her back with the fastening occurring on the wearer's front. In contrast, disposable absorbent pants typically have side seams along the wearer's side, which can make it difficult for a caregiver to fasten, unfasten, or even tear apart the side seams of the disposable absorbent pant, particularly on an active toddler. Another difference between diapers and disposable absorbent pants is that disposable absorbent pants can be slid on and off a wearer just like underwear.
One particularly beneficial improvement to disposable absorbent pants has been the creation of refastenable side seams in lieu of permanently bonded side seams. With the refastenable side seams, the disposable absorbent pant can still be pulled on and off like underwear, but also provides the option of being able to unfasten either side to determine whether a need exists to change the disposable absorbent pant. If the disposable absorbent pant is unfastened and it is determined that there is no need to change the disposable absorbent pant, the pant can be easily refastened. Additionally, if it is determined that the disposable absorbent pant is soiled and should therefore be changed, the caregiver can unfasten the garment along the refastenable seams and remove the garment without the necessity of removing the wearer's other garments. By removing the garment this way, the contents of the garment can also be more easily contained compared to having to slide the garment off the wearer in the manner of removing conventional underwear.
Many caregivers remove the disposable absorbent pants from a wearer by applying force to the side seams in opposing directions, whether the side seams are permanently bonded or refastenable. Generally, disposable absorbent pants having permanently bonded side seams tear adjacent the side seams or in another weakened area when such force is applied in the side seam region. It has also been observed that disposable absorbent pants having refastenable side seams sometimes tear at the side panels or the outer cover, or fastening components may become detached from the region of the garment to which they are bonded, or layers of the garment may start to delaminate, when such force is applied to the refastenable side seam region of the garment. Thus, if the refastenable side seams are too strong, or at least stronger than other materials in the garment, rather than becoming unfastened at the seam the other components of the garment may become irreparably damaged when any sufficiently large force is applied to the garment, either during normal wear and tear or when a caregiver is checking the status of the garment, thereby requiring replacement of the garment even if the garment is not soiled.
Furthermore, certain types of fasteners tend to increase in shear strength during wear and tear. For example, hook and loop fasteners tend to become more securely engaged during certain types of wear and tear because more and more hooks come into contact with more and more loops as the hook and loop fasteners are contorted during certain actions. Thus, by the time a caregiver checks the garment for any soiling, the refastenable seam may be more difficult to unfasten than it was when it was first fastened.
As another consideration, even if the peel strength of the refastenable seam is lower than the shear strength of the refastenable seam, the garment may still be prone to irreparable damage when high shear stresses are applied because greater force is required to cause shearing of a refastenable seam than to cause peeling of a refastenable seam, and the greater shear force that is needed to separate the seam has different effects on the garment than the relatively mild stresses needed to peel the seam. On the other hand, if the refastenable side seams have too little shear strength, fastener pop-opens are likely to occur as a result of even minimal shear stresses.
There is a need or desire for a refastenable disposable absorbent pant that minimizes the likelihood of irreparable damage resulting from the application of shear stress to the refastenable side seams.